Latitude E5470, BIOS 1.28.3, poor performance

This post is made for all the poor souls wondering why their Latitude (E5270/E5470/E5570 or Precision 3510) or other Dell made laptop may be suddenly suffering from poor performance.

It wasn't windows 21h2 update, it was Dell BIOS update pushed through official windows updates channel. The version in question is 1.28.3 - Build/Release date 10 Nov 2021. After update to 1.28.3 The whole machines performance stagnated to pathetic 15-20% of its capabilities. As for laptop equipped with 6300U, few tabs open in Firefox and video stream at 480p/720p 30fps was above it's limits on performance profile. Not to mention as simple things as literally LATENCY in switching between browser tabs.

SOLUTION: I found is to simply rollback BIOS to 1.27.3 and avoid this update all together, as long as Dell may be taking to (if even) rollback it's lousy update. It's outrageous how software QA stuff (if any) has simply failed to acknowledge this performance losses or pushed it anyway because of CVE / time constraints.